A prospective study of a titanium femoral component for cemented total hip arthroplasty.

The authors studied the clinical and radiographic results of a modern titanium-alloy femoral stem with a cobalt-chrome-alloy head for use in cemented total hip arthroplasty. One hundred sixteen hips (102 patients) were operated on using modern cement techniques and prospectively followed using the Hospital for Special Surgery hip rating system and standard radiographic criteria. At a mean follow-up period of 4.8 years (range, 2-8 years), 69 hips were rated excellent, 38 good, 4 fair, and 5 poor. A total of 13 femoral components (11%) were radiographically loose according to the criteria of Harris. In 11 of these loose femoral components, debonding or separation at the cement-prosthesis interface, was the initial cause of failure, with bone-cement interface erosions occurring later in five hips. Revision of a loose femoral component has been performed in three hips and is pending in two other hips (4.3%). Significant calcar resorption was seen in only 17 hips (14.6%), and serial measurements of distal femoral cortical widths showed no distal cortical hypertrophy except in one femur. The incidence of loosening with this cemented titanium-alloy femoral component (with a cobalt-chrome-alloy head) is much higher than published reports of similar cobalt-chrome-alloy stems. The authors have abandoned the use of titanium-alloy femoral components for cemented total hip arthroplasty.